20. The function P(4 )=0.54 converts Canadian dollars to Irish punts. The function s (p) =16P converts Irish punts to Austrian schillings. a. Write a function that converts Canadian dollars directly to Austrian schillings. b. How much is $1000 Canadian in Austrian schillings? c. Write a function that converts Austrian schillings directly to Canadian dollars. d. How much is 1000 schillings in Canadian dollars? 21. The speed of sound in air is about 330 m/s. a. Write a function () to represent the distance, d metres, a sound travels from a source in terms of the time, z seconds, since the sound was made. b. Write a function A() to represent the circular area, 4() square metres, within a distance d metres of the souce of a sound. c. Write a function () to represent the circular area, A, square metres, within which a sound can be heard within / seconds of the sound being made. d. Calculate the area within which the sound can be heard within 0.1 s of a car backfiring. Round your answer to the nearest ten square metres. e. If a sound is loud enough, how long does it take for the sound to be heard over an area of 1 km'7 Round your answr to the nearest tenth of a second